Eyewitness Memory Bob Campbell Lourdes University

Eyewitness Testimony z Loftus & Palmer (1974) z Contact speed was 31.8 mph z Smashed speed was 40.8 mph z 12% (contact) incorrectly recalled broken glass z 32% (smashed) incorrectly recalled broken glass

The Problem of Duality of Error in Law z Convicting the innocent z Acquitting the guilty z Beyond a reasonable doubt protects the individual at possible cost to society z Preponderance of evidence protects the society at possible cost to the individual z Hammond (1996)

Estimator and System Variables z Some factors that influence the accuracy of eyewitness testimony are beyond the control of the justice system z Other factors that influence the accuracy of eyewitness testimony can be controlled by the justice system z Wells (1978)

At the Scene of an Accident or Crime z The behavior of the officer at the scene of an accident or crime is a system variable which may alter the memory of the witness

Expectations z Hall et al. (1978) z Expectations of the police officer at the scene may influence the witness z The officer at the scene must be careful not to impart information to the witness either verbally or nonverbally

Type of Question Asked z Free Narrative such as “What did you see?” z Controlled Narrative such as “What was the assailant wearing?” z Interrogatory Reports such as “Where did the incident happen: in a lot, in the street, or on the sidewalk?”

Accuracy versus Completeness z Accuracy: Free, Controlled, Interrogatory z Completeness: Interrogatory, Controlled, Free z Officer on the scene must be aware of the need to balance the quest for accuracy with the need for completeness

The Effects of DNA Evidence z A recent study identified 62 individuals convicted of crimes they did not commit z 52 cases involved mistaken identification on the part of 77 highly confident eyewitnesses z Scheck, Neufeld, & Dwyer (2000) zAs of 2010, 254 individuals exonerated as a result of “project innocence”

The Guide z In 1999 the US Justice Department created a guide for law enforcement that details the handling of an eyewitness to an accident or crime z Panel consisted of 34 experts from law enforcement, the legal profession, and academia

Recommendations z Encourage rapport with the eyewitness and encourage them to talk freely z Conduct the interview at a slow pace and ask primarily open ended questions z Communicate your investigative needs to the witness

System Variables z Avoid surrounding a potentially innocent suspect with dissimilar fillers z The eyewitness should be instructed prior to viewing the lineups that the suspect may or may not be in the lineup

System Variables Continued z Present sequential rather than simultaneous lineups z Avoid giving the eyewitness feedback about the accuracy of the identification after a selection has been made z This must be done before assessing the confidence of the eyewitness

Eyewitness Research z Campbell (2003) z Control 45% accuracy 66% confidence z Exp 75% accuracy 74% confidence

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